The leukemias, though representing a minority of human cancers, serve as important, and perhaps the most accessible, models for the study of: (1) normal and neoplastic cell growth and regulation; (2) identification of transforming retroviruses and oncogenes; (3) development and understanding of anticancer drugs; and (4) evaluation of principles and practice of cancer therapy. Recently there have been substantial and significant advances in each of these areas, including: (1) the relationship between retroviruses, oncogenes, and leukemic transformation; (2) identification of probable human leukemia-related viruses (HTLV); (3) correlation between chromosome and gene rearrangements, oncogenes and leukemia; (4) interrelationships between oncogene products and cell growth factors and/or receptors; (5) new insights into molecular mechanisms of drug action and resistance; and (6) major advances in treatment of human leukemia, including new drugs, new uses of old drugs, and innovative approaches such as bone marrow transplantation or insertion of drug resistance genes. The goal of this meeting was to bring together major workers (both basic scientists and clinical investigators) in the area of leukemia. Discussions took place both during the plenary sessions, workshops, and poster sessions with an emphasis on exchange of new ideas. This meeting was extremely well-attended and stimulated research in this area. Because of the rapid progress in the field, this was a timely meeting and allowed maximum exchange of new information and thus aided and stimulated this already active area of research. (T)